The vegetation productivity and climatic productivity were estimated by using meteorological data from 18 weather stations in the Three-River Headwaters(TRH)during 1982 to 2013 and the satellite data form GIMMS and MODIS. Moreover,the effect of human activities were analyzed by calculating difference between vegetation productivity and climate productivity. The results showed that(1)the vegetation productivity,climatic productivity and the effect of human activities all had increased in the nearly 30 years,with the changing rates of 179,154 and 24 kg·hm~(-2),respectively;(2)climate change wasthe decisive factor impacting the vegetation productivity,and human activities accelerated its changing rate in the TRH. Especially,during the 21st century, the positive impact of human activity has become more obvious,with contribution rates of climate change and human activities to vegetation productivity being 87% and 13%,respectively.